Combined velocity and displacement pump or compressor



Feb. 19, 1935. J. CANNIZZARO 1,991,541

COMBINED VELOCITY AND DISPLACEMENT PUMP OR COMPRESSOR Filed Sept. 19,1933 s shee tssheet 1 IN VEN TOR.

Feb. 19, 1935: 1 J CANNIZiARO 1,991,541

COMBINED VELOCITY AND DISPLACEMENT PUMP 0R COMPRESSOR FiledSept. 19,1935 8 Shets-Sheet 2 INVENTOR.

Feb. 19, 1935. J, c zz o 1,991,541

NT PUMP OB COMPRESSOR COMBINED VELOCITY ANO DISPLACEME Filed Sept. 19',1933 8 sheets sheer. 3 I

INVEN TOR;

Feb. 19, 1935. J. CANNIZZARO 1,9919541 COMBINED VELOCITY ANDDISPLACEMENT PUMP OR COMPRESSOR Filed Sept. 19, 1933 8 Sheejs-Sheet 4INVENTOR.

Feb. 19, 1935. J. cANNlzz Ro' COMBINED VELOCITY AND DISPLACEMENT PUMP ORCOMPRESSOR Filed Sept. 19, 195:5 8 5heetsSheet,5

INVEN TORY,

COMBINED VELOCITY ANDDISPLACEMENT PUMP 0R COMPRESSOR Feb. 19, 1935. J.CANNIZZARO File d Sept. 19, 1933 8 Sheets-Sheet 6 Feb. 19, 1935. J.CANNIZZARO ,5

C MENT PUMP R COMP Filed Sept. 19, 1933 8 Sheets-Sheet '7 Feb. 19, 1935.v J. CANNIZZARO 1,991,541

COMBINED VELOCITY AND DISPLACEMENT PUMP OR COMPRESSOR Filed Sept. 19,1933 8 Sheets-Sheet 8 INVENTOR menus at. s, seas STATES IPATE n-vumol'rrAnn msrm 1am PM OB CONERESSQB v Joseph Cannizzaro, Union Gity, iii. 3.Application September 19, 1933, Serial No.69ibil82 v claims. (oi.103-128) ed, to rotate'o'n parallel shafts in a shell provided 15 withinlet and'discharge ports, wherein each impeller is providedwithconvexed' sides which are related to each other in such form as topermit the outer edges of the impeller to revolve in close proximity'with the adjacent concentric wall of '2 the shell and the adjacent sideof a coacting im-- peller, and in which the impellers, so formed andmounted, divide the space in the interior of the shell ,into separatechambers, which alternately undergo an expansion and diminution ofvolume as the impellers change position; and wherein the said expansionof volume causes aneflicient' suetion, and the said diminution ofvolume, causes an emcient compression or discharge pressure.

Another important object-oi the invention is to provide a pump orcompressor with helical impellers-as above described-Poi such form thatthat they are enabled to rotate, respectively, in

the same direction, so that centrifugal and propelling force (orvelocity energy) imparted to the 3 fluid is adequately conserved;so thatthe pump or compressor is not subjected to the serious losses of energyand eiiiciency known to occur in ordinary two-impeller type pumps andblowers, whose impellers are only adapted to rotate in respectivelyopposite directions, and in which the,

thereby, opposed velocities in the fluid are considerably dissipated,and whose eihciency is furthe: reduced by the tendency of such impellersto produce a volume expansion adjacent to the .45 discharge port,therebyv compelling the imperfectly applied force of velocity to workagainst a counteracting suction.

Another advantage derived from the provision of coacting helicalimpellers adapted to rotate in the same respective directions, is thatthe action of suction produced by centrifugal and propelling force iscoordinated with the action of suction produced by volume expansion;likewise, theac-- ,the shell on line 4-! of Figure 1.

charge caused by olume displacement; so that both methods of ac datingthe fluid mutuallyaugment the force and efiiciency of each other.

Another advantage of the invention resides in effectively combining theforce oi volume displacement with the force of velocity to reduce theRoss incident to the conversion of velocity energy to pressure energy,known to occur in ordinary velocity pumps and compressors.

Another advantage residing in the invention g is that it is enabled toefficiently pump viscous liquids-such as oil--for which ordinaryvelocity pumps are unadapted.

Another improvement residing in the invention 1 is thatit permits theeflicient application of the displacement principle at highrotative'speeds, resulting in higher thermal eiilciency and compactnessof the pumping plant, as compared to ordinary slow speed displacementpumps.

The basic principles of the present invention have been partly derivedand evolved from mechanical principles illustrated in Patent 1,874,239issued to myself on August 30, 1932.

I For a full understanding of the invention, reference is to be had tothe following description,

and the accompanying drawings in which,-

Figure 1 is a side elevation of the pump or compressor.

Figure 2 is a longitudinal vertical section of the base, on line 2-2 ofFigure 3. 0

Figure 3 is an end elevation of the invention. Figure 4 isa horizontalsectional view through Figure5 is an end view of a detached half sectionof the shell and, the adjacent part of the discharge chamber which isintegral therewith.

Figure 6 is an enlarged sectional view on line 6-6 of Figure 1.

Figure 'l is an enlarged end elevation of a pair of coacting helicalimpellers.

Figure 8 is an end view of one helical impeller removed from itsdetachable core.

Figure 9 is a side elevation of a detached core.

Figure 10 is an end view of the core shown in Figure 9.

Figure '11 is a sectional view on line 11-11 of Figure 12 showing amodified form of shell.

Figure 12 is a sectional view of the modified shell taken on line 12-12of Figure 11.

Figure 13 isan end view of two pair of cranks, with their respectiveconnecting links; arranged diagrammatically to show the relative angleatwhich one'pair of cranks is disposed in relation to the other pair. a

Figure 14 is a'perspective view of a pair of copumping operations.

acting helical impellers with a section of the shell, and'sbog in dottedlines the relative positions at which the impellers sides are disposedto each other; dotted lines also show, schematically, the relativepositions of the discharge chamber and discharge ports to the saidimpellers.

Figure is a view similar to Figure 14, except that the impellers areshown as having turned,-- in an anti-cloclswise directionthrough anangle of sixty degrees (60), as compared to the position in Figure 14.

Figures 16 and 17 are also similar to Figure 14, but the same pair ofimpellers are shown ashaving turned through angles of rotation of 120and rec", respectively, in an anti-clockwise direction, as compared tothe position shown in Figure 14.

Figures 13, 19, 20, 21 and 22 are partly diagrammatic and partlyschematic views, showing the same pair of impellers at successivelydifferent positions.

Figures 23 and 24 are diagratlc views illustrating the degree oiexpansion a chieved during Figures 25 and 26 are views of similar natureto Figures 18 to 22, inclusive.

Figures A, 22A, and A are views of similar nature to Figures 25 and 26,except that they illustrate operations that take place in the lower partof the shell, instead of operations in the upper part of the shell.

Figure 2518 is of a similar nature to the last named views except thatit shows the coordination of the operationspf a pair of helicalimpellers of left hand twist, with the operations of a pair of helicalimpellers of right hand twist.

Figure 27 is a diagram illustrating the order of discharge fromdifferent discharge ports.

Figure 28 is an end elevation of a pair of helical through a. right handimpeller at one end, through impellers of modified form.

Figure 29 is atop view of the modified impellers and a secti nd theshell. 9

Figure 3 is an end view-"partly in sectionof the modified inventionshowing the positions of the intake ports.

Figures 31, 32, and 33 are partly diagrammatic and partly schematicviews showing the same pair of 'modified impellers at successivelydifferent positions.

In the drawings, 15 designates a shell, which is transversely dividedinto two detachable halves; at their juncture the said halves of theshell are provided with an exterior discharge chamber 16 whose walls areintegral with the shell. Each half of shell 15 is provided with adischarge port 17 in its lower part, and a discharge port 18 in itsupper part; ports 17 and 18 communicate with said discharge chamber 16.

The interior of one half of the shell is separated from the interior ofthe other half by a partition plate 19, which is provided with twocircular apertures 20 and 20. The ends of the shell are closed by headplates 21 and'22.

Each head is provided with two exterior intake chambers 23 and 24, whosewalls-are integral with the head plate. Each head plate is also providedwith two intake ports 25 and 26, which communicate, respectively, withadjacent intake chambers 23 and 24. The head 21 is also provided withtwo cylindrical apertures into which are fitted respective bushingbearings 36 and 36'. The head 22 is likewise provided with cylindricalapertures into which are fitted bushing bearings- 38 and 38', andstufiing box glands 39 and 39. Head 21 is also provided with removablecaps 37 intake chambers at both ends of the shell.

and 37' which close the outer ends of the afore-, said cylindricalapertures.

I The shell 15 and its heads 21 and 22 are affixed to base 27, which issupported by standards 28; within the -base,and underlying theshell,--there is provided an intake chest 29,-whose walls are integralwith the base,-whlch is formed with upwardly curved ends to communicatewith $1116 e intake chest 29 is provided at its middle part with anouter aperture in the side of the base. In the present embodiment, theinvention is provided with a pair of right hand helical impellers 31,31, in one compartment of the shell and a pair of left hand helicalimpellers 31', 31', in the other compartment of the shell.

The impellers (31) are, individually, of such form that in cross-sectionthey have the shape of a triangle with convexed sides; andlongitudinally, the convexed sides of the impeller, whilemaintainingtheir uniformly triangular relation, extend helically aroundthe centre of the'said triangle, from one end of the impeller to itsother end; in the present instance, the amount of hellcal rotation ofthe impellers sides, has an angular value-from one end to the otherend,of 120.

The intake or suction end of each impeller "is provided with three inletpassages, respectively numbered 1, 2, '3, these inlet passages are openat the adjacent end of the impeller, and are formed with curved walls,which impart velocity to the entering fluid. For convenience inconstruction and assembling each impeller is made with a detachable core33, as in Figures 8, 9, 10, where it is seen that the walls separatingthe inlet passages are integral with the, core 33; each core has a.length equal to the full length of the shell. Two cores are provided fortwo pair of s glands 39, 39. The parts of the shaft that extendout fromthe shell are provided, respectively, with cranks 40 and 41, which areinterconnected by a link 42; the said shafts are also, respectively,provided with other cranks 43 and 44, which in relation to the firstnamed cranks are disposed at an angle of 90,- as shown in Figures 4 and13; cranks 43 and 44 are likewise interconnected by link 45. All cranksand links are balanced by suitable counterweights formed integral withsaid cranks. The purpose of the cranks and links is to communicaterotation of the driven shaft to shaft 35. p I I Adjacent to cranks and41, the shafts are, respectively, journaled in bearings 46, 46'; thepart of each shaft lying in its respective bearing is provided with anannular groove which communicates with an oil passage 47, (Fig. 4),which conveys oil to the respectively adjacent crank pin. The oil isprovided by oil cups 48; the outer ends of the shafts adjacent to cranks43 and 44 are journaled in bearings 49, 49; these bearings and theadjacent crank pins are also provided with the above describedlubricating system. The cranks and bearings adjacent thereto, aremounted in a protecting housing 50 which is affixed to base27, the crankhousing is provided with a in, that the chamber A is not, now, of auniform,

hinged cover 51. Shaft 35 terminates withinthe housing afterpassingthrough bearing 49,. while shaft 35' extends beyond the housing througha suitable aperture to provide connecting means with a suitable sourceof motive power.

The action of the pump-or compressor is illustrated in Figures 18 to 27,inclusive. Referring to Figure 18, it will be observed that the apexesor outer edges oi the impellers a, b, c, and a, b,

have turned in an anti-clockwise direction,

through an angle of 30; and it is shown theresectional area throughoutits length; and that I the part of chamber A which lies within theshaded area between'the line It and the apex b is of greatersectionalarea than other parts of chamber A, and that, therefore, chamber A hasundergone an expansion of volume. 'The expension of chamber A causessuction, which draws fluid thereinto, through the inlet passages 1,1';.it will be observed that inlet passage 1' registers with intake port25, so that it is wide open,

- expansion takes place in chamber A, in the reand that inlet passage 1is partly open in relation to port 26,. In Figure 20, it is shown thatfurther gion defined between and by the line h, and apexes a, and b, itis also shown that inlet passages 1, 1', are open to permit entry. offluid through ports 25 and 28 withwhich they, respectively, cooperate.

In the position of Figure 21, chamber A has undergone a still furtherexpansion, and inlet.

passage 1, has ceased to communicate with chamber A, however, inletpassage 1' is still open to permit entry of fluid into chamber A. The

land by the lines h,'K, and the apexes b, b; and

position of maximum expansion of chamber A, is shown in Figure 22, inwhich it is seen that the region of expansion is now deflned betweenthat inlet passages 1, 1' have both ceased to provide communicationbetween chamber A, and the source of intake. 'It will also be observedin Figure 22 that chamber A is separated from discharge port 18 by theapex b, and'that further rotation of the impellers will permit chamberA,

to discharge. through said port 18; and will also cause expansion andsuction in chamber 3. It will also be noted that-while the positions inFigurea 18 to 22, inclusive, illustrated the suction cycle ofchamber A,they, simultaneouslyrillustrated the discharge cycle of chamber C.

The discharge of fluid from chamber A,--which was about to begin inFigure 22,-'-is shown half I completed in Figure 25; in which it will beseen that discharge port-18 is in wide open communication with saidchamber A; and that there is no communication between chamber A and theintake ports 25 and 26, because inlet passage 1' is closed and apexes band '0'- separate chamber A from chamber -B; and as chamber A isundergoing a diminution of volume, the force of displacement resultingthereby,as well as the centrifugal force imparted to the fluid in thero-v tating helical chamber A,-acts to'expel jthe fluid from saidchamber A throughdischarge ports 18. It will also be observed thatexpansion Qfchamber B, and suction thereintoQ-which was :about to beginin Figure 22, -is shown half completed, and that suction of fluidthereinto is permitted through inlet passages 2, 2', which are,

respectively, open in relation to ports 25 and 26.

The discharge of fluid from chamber A is completed in the position shownin Figure 26, in which discharge therethrough.

Figure 14 is a perspective .view of the impellers in the position shownin Figure 18, while Figures 15, 16 and 1'7, are perspective views, whichrespectively correspond to Figures 20, 22 and 25.

The broken lines 1-1, 2-2, 3-3, 44, and 55 in Figure '20, point outcorresponding diagrammatic sectional or end views of the impellers.

in Figure 4, taken on the plane oi said lines 1--1, 2 2, 3-3, 4--4, 5-5,shown in Figure 4.

In Figure A, the impellers are in the same position shown in Figure 20except that the shell is assumed to have been turned over'thereby givinga view, of the bottom of shell and the impeilers mounted therein; sothat intake port 26 is at the left instead of at the right hand side,and the apexes sides and inlet passages of the impellers arecorrespondingly inv rted. Figures 22A, 25A and 25B are also view of thebottom of the shell and the impellers mounted therein.

Referring to Figures 20A and 20, it will be seen that while expansion ofchamber A is half completed, the expansion of chamber D is about tobegin and that inlet passage 1,--which is wide open and allowing theinflow of fluid to maximum discharge is passing through upper port 18,the discharge is zero at lower port 17,

Y and'vice versa. The expansion of chamber D and suction thereinto ishalf completed when the impellers are in the position shown in Figure22A in which it is seen that both inlet passages 1 and 2', are open topermit inflow of fluid intoD; it

. is also shown that discharge from F is half completed while inletpassage 3 adjacent to chamber F remains closed. Figure 22A is incorrespondence to Figure 22, wherein it is shown that chamber A hascompleted its suction cycle and is about to begin its discharge cycle.

' The expansion of chamber D is completed in the position shown inFigure 25A, in which position chamber D is about to begin its dischargecycle; inlet passage 1 is closed andremains closed throughout thedischarge cycle D. The views also show how chamber D passed from theupper part of the shell to the lower part of the shell; and how chamber0 passes from the lower to the upper part of the shell.

Referring to Figure 253 will be noted that this shows a pair of helicalimpellers having a left hand twist each left'hand impeller is rigidlymounted on a common shaft with a' corresponding right hand-impeller, sothat right hand rection. The operations of suction and discharge by theleft hand impellers are performed in the same way, as described inconnection with right hand impellers, however it will be observed inFigures A and 253, that while the right hand impellers are. about tobegin a discharge cycle at chamber D, the left hand impellers are at themid point-or maximum-in the performance oi their discharge cycle withrelation to discharge port 17'. It will be noted, therefore, that whenthe left hand impellers reach that part of their cycle wherein theyproduce maximum discharge at one port, the right hand impellers are at apoint of minimum-or zero-discharge in relation to a correspondingdischarge port, and vice versa.

Furthermore, it was pointed out in connection with Figures 20 and 20A,that when a pair of im= pellers is at maximum discharge in relation totheir upper discharge port, they are at minimum discharge in relation totheir lower discharge port and vice versa. The order of discharge fromdifierent discharge ports is illustrated by Figure 27, in which thedotted lines 1, 2,3,4, 5, 6, denote successive one-sixths of arevolution oi the impellers; and the areas 01' thetriangles A A A denotesuccessive volumes of fluid discharged through the upper port 18, of theright hand impellers; and the. triangles B B B denote successive volumesof fluid discharged through the upper port of the left hand impellers;likewise, triangles a a, a denote successive volumes of fluid dischargedthrough the lower port 17, of the right hand impellers; and triangles bb b denote successive volumes of fluid, discharged through the lowerport 17, of the left hand impellers. A maximum volume of discharge at adischarge port is denoted where one of the dotted lines passes throughthe wid est part of a corresponding triangle; while a minimum dischargeis indicated where the dotted line passes by the end of a triangle.

Assuming that dotted line 1 indicates the position shown in Figure 18,the volume of fluid discharged through port 18, is at minimum, or zero.On the line 2 discharge through port 18, denoted by A is at maximum,which corresponds with Figure 20; at line 3 discharge through port 18,is minimum,'corresponding with Figure 22; at line 4, discharge'throughport l8 denoted by A is at maximum corresponding withFigure 25.'Likewise, at line 2 discharge through port 17, isminimum, correspondingwith Figure 20A, at line 3 discharge through port 17 is at maximum,denoted by a, corresponding'with Figure 22A; at line 4, dischargethrough port 17, is minimum, which discharge through port 17, denoted by12 is at maximum, corresponding, respectively, with Figures 25A and 25B,

It is thereby demonstrated that the combined discharge from alldischarge ports, will produce a constant how of uniform volume.

In Figure 23, A, A, illustrate the position and volume of the rearwardhalf of the unexpanded chamber A, as in Figure 18, while in Figure 24, Aand A illustrate the position and volume of the forward half of saidchamber A, as in Figure 18; assuming that chamber A has moved to theposition shown in Figure 22, the position of the forward half of chamberA is indicated in Figure 24 by A and A A denoting the original area ofchamber A at the forwardend, while A denotes the original area ofchamber A at the mid-= section, where it is shown that the original areaof chamber A has been enlarged by the shaded area A+ and slightlydiminished by the area A-'-; the enlargedpart of chamber A extendstoward the forwardend, and has the lines d, e, and apex b, as boundarylines. Figure 23 is a similar view of the enlargement of the rearwardhalf of chamber A, in the position of Figure 22, the original area ofchamber A, at the midsection is likewise denoted by A and theenlargement thereof by A+, in like manner the enlargement extendsrearward between lines at, e, and apex b.

The modified shell illustrated in Figures 11 and 12 shows a method ofconstruction, that permits the use 05. an undivided shell; inthisinstance the shell 57, is continuous, and is provided with tworemovable liners 52, which hold in place the usual partition plate 19.The exterior of the shell, adjacent to usual discharge ports is providedwith discharge chests 53 and 54, integral with the shell, which areconnected together by a suitably formed detachable pipe 56; Thedischarge chest 54 is provided with the usual discharge aperture 55. i

The modified impellers 58, 58 shown in Figures 28 to 33, inclusive, eachhave the form,--in cross section of two segments of a circle, andlongitudinally, the convexed sides of the impeller, uniformly maintain amutual constant relation and extend helically around the centre, fromone end of the impeller to its other end; in the present instance, theamount of helical rotation of the impellers sides has an angularvalue,.trom one end to the other,of 90.

The coacting impellers 58, 58', are mounted on parallel shafts in ashell 59, whose concentric walls permit the impellers outer edges torevolve in close proximity therewith. Each impeller is provided with twoinlet passages-1, 2 and 1", 2', which cooperate with appropriatelylocated intake ports 61, 61, in head 62; in all other respects theconstruction of shell, base, and driving mechanism would be as describedbefore.

In Figure 31, chamber A is aboutto expand, thereby beginning its suctioncycle, and drawing iiuid thereinto through inlet passages 1 and 1', andintake ports 61 and 61', as is further shown in Figure 32. Thecompletion of this suction cycle in chamber A, is shown in Figure-33.Figures 31 to 33, inclusive, simultaneously illustrate successive stagesof the discharge cycle oi. chamber B; also showing, that inlet passage 2adjacent to chamber B, remains closed during the said discharge cycle,thereby preventing communication between chamber B, and the source ofintake therethrough. I

Having thus described the invention, and some of its modifications, Iclaim:

1. Ir. a pump or compressor, substantially as shown and described, thecombination ot a shell, a partition in theshell dividing said shelltransversely into two compartments, discharge ports in each compartment,a common discharge chamber around the exterior of the shell,communicating with the said discharge ports, a pair 01' right handhelical impellers,which in crosssection are, respectively, triangularwith convexed sides-mounted to rotate in one compartment of the shell,and cooperating with the shell to form chambers whose respective volumesvary as the impellers change position, a pair of left as the impellerschange position, inlet passages in the impellers, heads closing the endsof the shell, intake ports in the heads cooperating with the inletpassages in the impellers, intake chambers in the heads, a basesupporting the shell, a common intake chamber in the base communicatingwith the intake chambers in the heads, means for rotating the impellers,respectively, in the same direction, as and for the purpose set forth. c

2. In a pump or compressor, substantially as shown and described, thecombination of a shell,

a partition in the Shell dividing said 'shell'into" two compartments,discharge ports in each-compartment, a common discharge chamber aroundthe exterior of the shell, communicating with said discharge ports, apair of right hand helical impellers,which in cross-section are,respectively, in the form of two segments of a circle,- mounted torotate in one compartment of the shell, and cooperating with the shellto form chambers, whose, respective volumes vary as the impellers changeposition, a pair of left hand helical impellers,which in cross-sectionare, respectively, in the form of two segments of a circle,mounted torotate in the other compartment of the shell, and cooperating with theshell to form chambers, whose respective volumes vary as the impellerschange position; inlet passages in the impellers, heads closing the endsof the shell, intake ports in the heads cooperating with the inletpassages .in the impellers, intake chambers in the heads, a basesupporting the shell, a common intake chamber in the"ba'se communieatingwith the intake 'chambers in the heads, and means for rotating theimpellers, respectively, in the same direction, as and for the purposeset forth.

3. In a pump or compressor, the combination of a shell, one or more pairof helical impellers,- which in cross-section are, respectively,triangular with convexed sides, .mounted to rotate in the shell, andcooperating with the shell to form chambers which respectively, vary involume as the impellers change position-causing, alternately, suctionand discharging pressure in said chambers,means cooperating with theimpellers for introducing fluid to the chambers, means cooperating withthe impellers, for discharging fluid from said chambers, and means forrotating the impellers, respectively, in the same direction.

- of a shell,'one or more pair of helical impellers,-

which isv cross-section are, respectively, in the form of two segmentsof a circle,mounted to rotate in the shell, and cooperating with theshell, to form chambers whose respective volumes vary as the impellerschange position,- causing, alternately, suction and discharging pressurein said chambers,--means cooperating with the impellers for introducingfluid to said chambers, means cooperating with the impellers fordischarging fluid from said chambers, and meansfor rotating theimpellers, respectively, in the same direction.

5. In a pump or compressor the combination of a shell, one or more pairof helical impellers with convexed sides, mounted to rotate in theshell, and cooperating with the shell to form' chambers, whoserespective volumes vary as the impellers change position,causing,alternately, suction and discharging pressure in said chambers,-meanscooperating with the impellers for introducing fluid to said chambers,means cooperating with .the impellers for discharging fluid from saidchambers, and means for rotating the impellers, respectively, in thesame direction.

6. In a pump or compressor the combination of a plur f helical impellerswith convexed sides mogifed to rotate and cooperate to form one ormofechambers whose respective volumes vary as the impellers changeposition,-causing, alternately, suction and discharging pressure insaid, chambers, means for introducing fluid to said chambers, means fordischarging fluid from said chambers, and means for rotating'theimpellers, respectively, inthe same direction.

'7. In a pump or compressor the combination of a shell, a pair ofhelical impellers,which in cross-section are triangular with convexedsides,- mounted to rotate in the shell and cooperating with the shell toform chambers whose respective volumes vary as the impellers changeposition,--causing, alternately, suction and discharging pressure. insaidchambers, means ior discharging fluid from said chambers, means forintroducing fluid to said chambers, and means for rotating theimpellers, respective y, in the same direction.

' JOSEPH 'CAN'NIZZARO.

